J/ApJ/988/L63ivo://CDS.VizieR/J/ApJ/988/L63doi:10.26093/cds/vizier/ba-yw/wgdCDSMaciejewski G.Loboda W.2026-07-02T12:01:21Z2026-01-30T12:55:17ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frmultiple-starsexoplanetsvisible-astronomyWe report the detection and characterization of TOI-201 c, a long-period transiting companion to the warm Jupiter TOI-201 b. Its presence was first inferred from high-amplitude transit timing variations (TTVs) in TOI-201 b, pointing to a massive outer body on a 7.7_-0.6_^+1.0^yr eccentric orbit. This prediction was confirmed when Transiting Exoplanet Survey Satellite observed a transit of TOI-201 c, precisely constraining its orbital geometry. A joint fit to TTVs, transit photometry, and archival radial velocities yields a mass of 14.2_-1.2_^+1.0^M_Jup_ and an eccentricity of 0.643_-0.021_^+0.009^. The mutual inclination between planets b and c is 2.9_-4.4_^+4.8^{deg}, indicating a nearly coplanar architecture. Long-term numerical integrations confirm dynamical stability over gigayear timescales and predict that transits of TOI-201 b will cease within a few thousand years. TOI-201 c ranks among the longest-period transiting planets with well-constrained properties. Its detection via TTVs, followed by a confirmed transit, represents a rare observational sequence and highlights the power of TTVs and photometric monitoring to uncover distant companions. The TOI-201 system offers a valuable laboratory for testing models of giant planet formation, migration, and secular evolution in multiplanet systems.2025ApJ...988L..63Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/988/L63CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/AJ/161/235 : Radial velocity of TOI-201 (Hobson+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/988/L63https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/988/L63http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/988/L63https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/988/L63https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/988/L63http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/988/L63GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/988/L63/ttimesTransit times for TOI-201 b and TOI-201 crecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSectorTESS sectorobs.fieldintTmidMid-transit time in Barycentric Julian date in Barycentric Dynamical Time (BJD_TDB)dtime.epochdoubleE_TmidPositive mid-transit time errordstat.error;stat.maxdoublee_TmidNegative mid-transit time errordstat.errordoublePlanetPlanet namemeta.id;meta.mainchar